3D Viologen-based covalent organic framework for selective and efficient adsorption of ReO4−/TcO4

• Published in: Separation and purification technology Vol. 312; p. 123409
• Main Authors: Chen, Xiao-Rong, Zhang, Cheng-Rong, Jiang, Wei, Liu, Xin, Luo, Qiu-Xia, Zhang, Li, Liang, Ru-Ping, Qiu, Jian-Ding
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2023
• Subjects: Adsorption; Anion exchange; Cationic covalent organic frameworks; TcO4−/ReO4; Three-dimension; Three-dimension; Anion exchange; TcO4−/ReO4; Adsorption; Cationic covalent organic frameworks
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.123409

[Display omitted] •A 3D cationic covalent organic framework (TFAM-BDNP) was synthesized via Zincke reaction.•TFAM-BDNP exhibits high adsorption capacity and extremely fast exchange kinetic for ReO4−.•TFAM-BDNP demonstrates remarkable selectivity for ReO4−.•TFAM-BDNP has outstanding removal efficiency of ReO4− from simulated Hanford flow sample. Due to the long half-life and high environmental mobility, the selective and efficient capture of TcO4− from nuclear effluents is very important, but it is still very challenging. Herein, we design and synthesize a novel three-dimensional (3D) cationic covalent organic framework (TFAM-BDNP) via Zincke reaction for selective capture of TcO4−/ReO4−. TFAM-BDNP exhibits high adsorption capacity (998 mg g−1) and extremely fast exchange kinetic (60 s) for ReO4− (the non-radioactive alternative to TcO4−), attributing to the open 3D hydrophobic channels, abundant active sites, and high chemical stability. More importantly, TFAM-BDNP shows good adsorption performance for ReO4− in the presence of significant excess competing anions with a wide pH value range of 2 to 12. Under complex simulated Hanford flow sample, TFAM-BDNP has outstanding removal efficiency of ReO4−. The adsorption mechanism of ReO4− is mainly caused by anion exchange process. This study provides a novel adsorbent for efficient capture of TcO4−/ReO4− in complex environmental systems and exploits an effective strategy for broadening the types of 3D COFs.